An Asda payroll clerk who boasted her bosses "did not have a clue" that she was paying herself extra wages has been jailed for two years.

Over 18 months, Janette Norman fleeced the supermarket giant of £31,070 by reactivating the account profile of an ex-employee and amending the bank details to her own.

The 51-year-old also "led her son astray" and paid an additional £5,937 into his bank account, a court heard.

Both were based at Asda's store in Greenhithe, with 28-year-old Christopher Norman working in the meat and produce department.

The additional wages were processed as missed breaks, extra hours or public holiday pay.

During her scam there were a number of text messages between mother and son which depicted her "explicit trickery", said prosecutor Don Ramble.

In one she boasted: "They don't have a clue" and in another she wrote "I'm getting good at cock-ups. I did it last month too. They shouldn't leave me on my own!!"

Janette Norman of Chaucer Way, Dartford, admitted two offences of fraud. Christopher Norman, who now works as a bus driver, denied money laundering but was found guilty by a jury at Maidstone Crown Court.

He was given nine months' imprisonment suspended for 18 months, with 150 hours of unpaid work and court costs of £2,600 to pay.

The court was told Janette Norman started to steal the money, which equated to £1,700 a month, in November 2013 after she struggled to meet her rent, payday loans and other debts.

"You abused your position as a payroll clerk in a calculated and potentially very effective way" - Judge Jeremy Carey, to Janette Norman

None was spent on a luxury lifestyle or "flash holidays", said her barrister Keith Yardy.

However, on sentencing them, Judge Jeremy Carey said Janette Norman had shown a "very glib and off-hand" attitude, which did not tally with her assertions that she committed the fraud out of necessity or financial pressure.

He added that she saw the extra income as easy-pickings.

"You abused your position as a payroll clerk in a calculated and potentially very effective way. There was significant planning and your criminality was carried out over a sustained period," said Judge Carey.

"You Christopher Norman are in a very different category to your mother in terms of your offending. But you were quite plainly a knowing participant in money laundering, and for your own benefit."

During his trial, Christopher Norman, of Attlee Drive, Dartford, told the jury that he had also been a victim of further fraud committed by his mother taking out loans in his name and using his credit card.

Peter Briegel, defending, said he had been "led astray" by his mother and neither have spoken to each other since their arrests.

Neither had any previous convictions.